Phospholipids

• What should you be able to describe by the end of the video?

  Structure and function of phospholipids
• What does a triglyceride molecule contain?

  One glycerol and three fatty acids
• Why are triglycerides considered non-polar?

  They are uncharged molecules
• What property makes triglycerides useful for waterproofing?

  They are hydrophobic and do not dissolve in water
• How do phospholipids differ from triglycerides in structure?

  Phospholipids have two fatty acids and phosphate
• What charge does the phosphate group in phospholipids carry?

  Negatively charged
• Why is the phosphate group considered hydrophilic?

  It attracts water molecules
• What do the tails of phospholipids represent?

  Two fatty acid molecules
• How do phospholipids behave in water?

  They form a bilayer with heads in water
• What is the structure formed by phospholipids in water called?

  Phospholipid bilayer
• What is the significance of the phospholipid bilayer?

  It forms membranes around and within cells
• What family of lipids does cholesterol belong to?

  Sterols
• What are the two key features of the cholesterol molecule?

  Hydrophilic hydroxyl group and hydrophobic rest
• How does cholesterol interact with cell membranes?

  It inserts into membranes due to its structure
• What role does cholesterol play in cell membranes?

  It controls the fluidity of membranes
• How is vitamin D produced in the body?

  From cholesterol in response to UV light
• What is the function of bile produced in the liver?

  To increase lipid digestion by lipase
• What hormones are based on cholesterol?

  Estrogen and testosterone
• What are the properties and functions of cholesterol?

  • Part of sterols family
  • Hydrophilic hydroxyl group
  • Hydrophobic structure
  • Inserts into cell membranes
  • Controls membrane fluidity
  • Precursor for hormones (e.g., estrogen, testosterone)
  • Used to make vitamin D
  • Produces bile in the liver
• What are the properties and functions of phospholipids?

  • Composed of glycerol, two fatty acids, and phosphate
  • Contains hydrophilic head and hydrophobic tails
  • Forms phospholipid bilayer in water
  • Essential for cell and organelle membranes